RFR: tester: allow configurable allowlist

[Robin Westberg]

On Sat, 29 Aug 2020 13:34:56 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review that patch that enables a configurable allowlist for the tester bot. I also added a unit test for the new
> functionality.
> Testing:
> - [x] `make test` passes on Linux x64
> - [x] Added a new unit test
> 
> Thanks,
> Erik

Looks good!

-------------

Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/753